Synthesis of well-defined multi-block copolymers by means of solid phase synthetic method using telechelic polymers

我们开发了一种新的方法来合成具有羟基、氨基、羧基、巯基和1,3-丁二烯基的远链聚合物。该方法涉及苯乙烯，1,3-丁二烯和异戊二烯的阴离子活性聚合物与具有保护官能团的卤代烷基化合物的反应。所得聚合物均具有可控的分子量和较窄的分子量分布。更重要的是，上述反应定量地引入了官能团的度。通过NMR， IR， UV和新开发的TLC-FID方法成功地分析了末端官能团。这些官能团可以转化为活性更高的酸酐、氯化酸和氯甲酸酯部分。同样，利用阳离子活性聚合物合成远螺旋聚合物目前也在研究中。为了制备结构明确的多嵌段共聚物，进行了胺化聚苯乙烯与羧化聚异戊二烯的模型反应。发现该反应可以定量地产生相应的嵌段共聚物。在聚苯乙烯凝胶上进行了类似的反应，然后从凝胶中去除，得到了产率高达90%以上的嵌段共聚物。目前正试图通过在聚苯乙烯凝胶上顺序加成不同的远旋聚合物来合成定义明确的多嵌段共聚物。

We have developed new methodology for synthesizing telechelic polymers with hydroxy, amino, carboxy, mercapto, and 1,3- butadienyl groups. The methodology involves the reaction of anionic living polymers from styrene, 1,3-butadiene, and isoprene with haloalkyl compounds with protected functional groups. The resulting polymers all were observed to possess controlled molecular weights and narrow molecular weight distributions. More importantly, the degrees of functional groups are quantitatively introduced by the above reactions. The analyses of end functional groups were successfully performed by NMR, IR, UV, and the newly developed TLC-FID methods. These functional groups could be transformed into more reactive acid anhydride, acid chloride, and chloroformate moieties. Similarly, the synthesis of telechelic polymers using cationic living polymers are under investigation at the present time.In order to make multi-block copolymers with well-defined structures, a model reaction between aminated polystyrene and carboxylated polyisoprene was carried out. The reaction was found to proceed quantitatively to produce the corresponding block copolymer. The similar reactions on polystyrene gel have been carried out followed by elimination from the gel to afford the block copolymers in high yields more than 90%. The well-defined multi-block copolymers are now attempted to synthesize by sequential addition of different telechelic polymers on polystyrene gel.